This section provides background information related to the present disclosure which is not necessarily prior art.
Certain polymerization processes, especially olefin polymerization processes, are sensitive to poisons that can reduce the catalyst activity. There are commercially available adsorbents that can be used to treat the various streams of materials going into the polymerization reactor. For example, WO 2004/033507 discloses that dual adsorbents can be used to remove impurities from a cycle stream in a polymerization process. However, in conjunction with the inventive activities, it has been surprisingly found that certain non-conjugated diene monomers may react with components of the polymerization reactor to form undesirable oxygenates. It would be desirable to reduce or eliminate such oxygenates that otherwise poison the catalyst.
Porous inorganic solids have found great utility as catalysts and separation media for industrial application. In particular, mesoporous materials, such as silicas and aluminas, having a periodic arrangement of mesopores are attractive materials for use in adsorption, separation and catalytic processes due to their uniform and tunable pores, high surface areas and large pore volumes. The pore structure of such mesoporous materials is large enough to adsorb large molecules and the pore wall structure can be as thin as about 1 nm. Further, such mesoporous materials are known to have large specific surface areas (e.g., 1000 m2/g) and large pore volumes (e.g., 1 cc/g). For these reasons, such mesoporous materials enable reactive catalysts, adsorbents composed of a functional organic compound, and other molecules to rapidly diffuse into the pores and therefore, can be advantageous over zeolites, which have smaller pore sizes. Consequently, such mesoporous materials can be useful not only for catalysis of high-speed catalytic reactions, but also as large capacity adsorbents.
Mesoporous organosilica (MOS) supports are conventionally formed by the self-assembly of the silsequioxane precursor in the presence of a structure directing agent, porogen and/or framework element. The precursor is hydrolysable and condenses around the structure directing agent. For example, Landskron, K., et al. report the self-assembly of 1,3,5-tris[diethoxysila]cylcohexane [(EtO)2SiCH2]3 in the presence of a base and the structure directing agent, cetyltrimethylammonium bromide. Landskron, K., et al., Science, 302:266-269 (2003).
US2012/0059181 reports the preparation of a crystalline hybrid organic-inorganic silicate formed from 1,1,3,3,5,5 hexaethoxy-1,3,5 trisilyl cyclohexane in the presence of NaAlO2 and base. US2007/003492 reports preparation of a composition formed from 1,1,3,3,5,5 hexaethoxy-1,3,5 trisilyl cyclohexane in the presence of propylene glycol monomethyl ether. U.S. Pat. No. 7,947,799 discloses high organic group content-periodic mesoporous organosilicas having [ER]n rings interconnected by E′ atoms, where n is greater than 1, and E and E′ are inorganic elements. Voort V. et al., report in Periodic Mesoporous Organosilicas: From Simple to Complex Bridges; A Comprehensive Overview of Functions, Morphologies and Applications various periodic mesoporous organosilicas and mentions, at paragraph 4.1.3, bridges of Ni(II) alpha-diimine complexes showed high activity in the ethylene polymerization at a wider range of temperatures than the homogeneous complexes (see Chem. Soc. Rev., 2013, 42, 3913).
However, the use of a structure directing agent, such as a surfactant, in the preparation of an organosilica material, such as a MOS, requires a more complicated, energy intensive process that limits the ability to scale-up the process for industrial applications. Furthermore, introduction of additional agents or processing steps to remove structure directing agents from MOS can introduce additional reactive and undesirable compositions into the system, potentially leading to additional species or catalyst poisoning. Therefore, there is a need to provide an organosilica materials having desirable pore size, pore volume and surface area, which can be prepared in the absence of a structure directing agent, a porogen and/or a framework element (aside from C, O, Si and hydrogen). Such materials will be described further herein. For more information, see also, U.S. Provisional Application No. 62/091,071 filed on Dec. 12, 2014 and U.S. Provisional Application No. 62/091,077 filed on Dec. 12, 2014, the disclosures of which were fully incorporated herein by reference above.